The goal of the proposed research is two-fold. First, does a time-invariant magnetic field, between 1.5 Tesla and 17 Tesla, affect gene expression and cell differentiation? Second, is magnetic levitation a suitable ground-based alternative for space-based orbital freefall experiments? For the levitation studies we plan to monitor gene expression via microarray analysis and osteoblast differentiation by quantitative real-time PCR. The murine calvarial osteoblast cell line, MC3T3-E1, is the model biological system for these experiments. Magnetic levitation occurs when a magnetic force counterbalances a gravitational force. Placing a biological (diamagnetic) object in a strong magnetic field and a strong magnetic field gradient creates a magnetic force on the system. A magnetic force is the only means to reduce the net gravitational force on a system to less than 1-g. Osteoblast cells have a demonstrated sensitivity to gravitational loading conditions. These cells will be cultured in a unique 17 Tesla/50 mm warm bore superconductive magnet to study the effect of a net 'gravitation force varying from 0-g through 2-g on gene expression and osteoblast biochemical markers. The magnet is capable of sustaining continuous levitation for weeks at a time. Monitoring bone osteoblast differentiation and function under conditions where net the gravitational force is a variable, represents a unique venue for understanding the effect of gravitational forces on bone growth/resorption. This is a new area of scientific exploration that has not been explored because of limited access to magnet systems capable of magnetic levitation. Furthermore, with this instrument it is now possible to study biological function at 0.38 g and 0.167 g, thus providing ground-based simulations of the gravitational forces experienced on the surface of mars and the moon, respectively. [unreadable] [unreadable]